Electron discharge device circuit



Sept. 21, 1943- A. M. SKE LLETT ELECTRON DISCHARGE DEVICE CIRCUITOriginal Filed on. gs, 1941 2 Sheets-Sheet 1 FIG? J'ECONDARI EECTRONEHITTER COLLECTOR aznrcron :1. ECTROOE u H N E vm mu m aw M A. w y? BI$20Z5JOJ$l045505560 CURRENT IN COIL -MILLIIMPERE$ I I I Sept. 21, 1943.A. M. SKELLETT 2,329,792

' ELECTRQN DISCHARGE DEVICE CIRCUIT Original Filed Oct. 23, 1941 2Sheets-Shae} 2 FIG. 7 4 Off f :z; 20 arr} CURRENT IN COIL -MILLIAMPEREllll All! J0 OFF, on 3 E20 01v 1 In arr I 3:

i" a '0 In E0 MO I I 510 8 T i on & i M 1 /NVENTOR E a; A. M SKELLETT UBYQMX Patented Sept. 21, 1943 nmc'rnonnrsonAnennnvron 01mm- 1" AlbertM/Skellett, Madison, N. a, assignor to BellTelephone Laboratories,Incorporated, New York, N. Y., a corporationofNew York Originalapplication October 25 ,1 91 1,:;Serial No. 7

416,155. Divided'and this application'Septem ber1,1942,se i ineiaesis, p

' as Claims.

This application is a division of my application Serial No. 416,155,filed October 23, 1941, for Electron discharge device circuits, issuedas United States Patent No. 2,309,019 of January This invention relatesto electron discharge devices and, ,more particularly, to electronicvacuum tubes of the secondary electron emission type and circuitsincorporating the same. More specifically, the invention relates tomodifica-' I means and method of regulating or. controlling the on andoff properties or conditions of a trigger device comprising a vacuumtube of the secondary. electron emission type. c

A feature of the invention comprises controlling the operating conditionof such a trigger device by means of a magneticfield, the lines of forceof which may extend either parallel to or perpendicular to the axis ofthe device.

A more complete understanding of theinven- V 25.,cathodaparticles-that;maybe released from-said tion will be obtained from thedetailed'description that follows, read with reference to' the appendeddrawings,- wherein: i

, Figs. 1, 2 and 3 illustrate arrangements for associating a magneticfield with an electronic device or vacuum tube;

Fig. 4 shows a circuit arrangement in accordance with the invention inwhich a secondary electron emission type vacuum tube has anelectromagnet associated with it, as ingthe arrangement of Fig. 1, toprovide a magnetic field parallel to or along the axis of-thetube;

Fig. 5 illustrates the electrode arrangement in the tube of Fig. 4, andwill bereferred to in describing the action of the magnetic field on theprimary electrons emitted through the window or aperture in the primaryanode;

Fig/Sis a typical operating characteristic of the tube,-being a plot ofmagnetizing currentiin the magnetic field producing coil of Figs. 1 and4 versuscathode-primary anode current, evidencing two critical primaryanode current off and two critical primaryianode current"on .values ofmagnetizing current for a given setof :potential conditions on. the tubeelectrodes? Fig. 7 shows a family of curves illustrating how thesecritical ofi-and on magnetizing current values are affected byvariationin deflector electrode potential;

Fig. 8 is a schematic of a vacuum tube such as 1 shown in Fig. 4, butwith the magnetic field'producing arrangementof Fig. 2 to provide a mag-Fig. 9 shows a family of curves illustrating how the critical .offand:on values of magnetizing s current in the coil vary with variationin de- (o1; est-+27% I I fl r el t ode rq enti ndv he i ci 99 t= r 1 them ne zin un nti l e thecoil-or electromagnet'ofFigs. 2 and-5; and

Fig.,l',0; shows a closed ring-pulse counting cir- 5 cuit embodying themagnetically qqntrolled secnda le t n emit u m: rie e ..wbe o thisinvention.

a Inmy test 3 1 7 i ido d a y wn tube having a trigger characteristic,i; e g-it may 10 be substantiallyinstantaneously energized ordeenergized dependent on its initial". condition. For a detaileddescription oitzthe construction and of circuit applications of thistube reference may be had to Patent -2,2;93,-17,'7., ;but,-.in general,"15 the .tubecomprises a cathode and inputcontrol -grid;. a primaryanode having: an aperture or window therein for the, passage. or. escapetherethrough of primary 7 electrons originating at the cathode; asecondary electron'emitting electrode '20. or auxiliary anode j havingan; emissionl er atic greater than unitypa collector electrode or-grid.forcollecting secondary electrons released when primary: electronsbombard. the; auxiliary g eleco ma d: s. defl ct rw ec od x o oll ctcathode, and for bending or deflecting frqmstheir normal paths primaryelectrons that pass ,out-

, wardly through; the aperture -in; the:'primary,

go put grid and/or theauxiliary anode to trigger the tube on or ofi as'.in Patent 2,293,177,,the

' trigger action, inacoordance with this. invention,

maybe effected by magnetic or electromagnetic means, the presence orabsence/and the density of-.magnetic fluxmparallel or perpendicular to.the axisof the tube determiningwhetherI-the 1 primary electron streamis incident .on the auxiliary'anode andwhether the latter .is'at itsfloating potential. and i the input gridat a potential substantiallyabove cathode-primary anode our? rentcut-offp, I .1-

Figs. 1,2 and 3.illustrate how magnetic flux.-

j producing mean maybe associated with a vacuum tube In of the generaltypedisclosedjin my aforementioned patent. .In, Fig. ;1," anelectromagnet 5, shown in cross section, surroundsthe tube, and when,energizing current flows 'in' the electromagnet-jit produces. magnetic.f ,lux-in a .direction pBIaHBTtQf theiaxis ofthe tube; Elli Fig. 2, theelectromagnet 5' surrounds a. yoke H of bombarding the auxiliary anode.In the particular case, this occurred at about 34 milliamperes, atwhichthe anode current rose to'about- 12 milliamperes. Further'reductionin the coil current causes the anode current to increase slightly un-Fig. 6 was obtained but with the deflector electrode at +45 volts, thetube was caused to trigger on initially with a current of only 9.5milliamperes in the coil 5. Fig. '7 shows how the critical curents A, B,C, D for the coil current vary with variation in deflector electrodepotential. These characteristic curves were obtained with the primaryanode and the collector grid at +180 volts, and with the input gridbiased to 22.5 volts. The positive and negative signs on the coilcurrent scale indicate the direction of current flow through the coil,i. e., positive currents produce a magnetic field whose tendency is todeflect the primaryelectron stream toward the path 0, negative currentsproduce a magneticfleld of reversed polarity from that of 1 the fieldproduced by the positive currents and whose tendency is to deflect theprimary electron stream toward'path'a. j

The specific description hereinabove has been with respect to a controlcoil that produces a magnetic field substantially parallel to the axisof the tube. The arrangements of Figs. 2 and 3 enable magnetic controlof the primary electron streams'by means of a magnetic field extendingperpendicular tothe axis of the tube. Fig. 8 illustrates the relation tothe electrodes of tube I of the magnetic lines of force provided by themagnetic yoke and coil 5' of Fig. 2. In a specific embodiment of theinvention, the yoke was of iron, the coil consisted of 19,000 turns ofNo. 36 wire and had a resistance of 3,660 ohms. The gap between thefaces of yoke ends'fi was about 1 inches and milliamperes of directcurrent in the coil 5 produced a field of 50 gauss at the center of thegap. The direction of the magnetic field with respect to the electrodeshas been'd'etermined to be somewhat critical, best results beingobtained when the direction of the field in the gap was set at an angleof 4.0 degrees with respect to the plane of the collector grid, althoughdeviations of the order of a few degrees from this condition could betolerated. A typical cycle of on and ofi operation for this arrangementwould be similar to that shown in Fig. 6 for the control coilarrangement of Fig. 1. With the arrangement of Fig. 2 and Fig. 8,however, the direction of current flow in the coil 5' may be such as toproduce magnetic linesof force in either direction across the gap'between yoke ends 6, and yet enable substantially the'same oil and oncycle to be obtained; The arrangement "of Fig. 2 provides the equivalentof an ordinary relay. As with the arrangement of Fig. '1, thesensitivity of the trigger control i dependent on the potential at whichthe deflector electrode is maintained. Fig. 9 shows a family of coilcurrent-deflector potential curves for the arrangement of Fig. 2, inwhich the primary anode and collector grid of tube I0 were at+180 voltsand the input grid was at a potential of 22.5 volts iliary anode at itsfloating potential.

Fig; 10 shows a closed Jring pulse counting circuit comprising aplurality of stages of the'mag- .netically controlled trigger vacuumtubes of this invention. Each tube I01-I05 is similar to tube I ,ID ofFig. 4.1 The magnetic field producing boil for each tube comprises two.separate windings L1, L2, the'windings L1 being connected in parallelacross the terminals 50 on which are impressed the pulses to be counted,and each wind- -ing L being connected in aprimary anode potential leadfrom the high potential terminal of source 25', the windingJL2 of aparticular tube being connected in theprimary anode potential .supplylead of the preceding tube in thering.

Biasingpotential for the input grids of the tubes rectly, and theauxiliary anode, through a resistor 27' are connected to the potentialsource 25, while the deflector electrodes are connected to anintermediate point on the source 25. The resistors 2I'., 28', 29 areproportioned so that the auxiliary anodes normal potential, 1. e., whenthe tube is in ofi condition, is at least above the lower zero currentpotential of .the auxiliary anode. The primary anodes of succeedingtubes are connected through condensers C1C5. The operation of thiscircuit is as follows: In order to fire or trigger on any one tube inthe ring, both windings L1, L2 associated with that tube must beenergized. If it is assumed that tube I01 has already been fired or isin its on condition, its cathode-primary anode current flows through theL2 winding of tube I02, which produces av magnetic field in tube I02 ofa strength substantially less than that required to trigger it on. Whena current pulse is impressedon the terminals 50, each winding L1produces a mag- I .netic field in its associated tube that is ofstrength substantially less than that required to oll, each L2 windingbeing of sufficient resistance to cause such'change in the primary anodepotential of a tube as it triggers on that, acting through the couplingcondenser, inthe present instance C2, it momentarilyreduces the primaryanode potential of the preceding tube to such a value that insuflicientprimaryelectrons reach the auxiliary anode 'thereofto maintain the aux-The fall of the auxiliary anode potential to its normal potential causesthe input grid to reduce still further the flow of primary electrons intube I01 and, in the absence of energizing current in both of thewindings L1, L2 associated with tube I01 the latter remains triggeredoil. As successive current pulses are impressed through terminals 50,the tubes fire in succession around the ring, the 'register'R in theprimary anode lead for tube lfleregistering every fifth pulse received.

Although this invention has been. disclosed with reference to certainspecific embodiments, it is to be understoodthat the invention is notlimited thereto, but that such embodiments rep resent what are believedat this time to be the best; mode of applying the invention.

ary electron section, said primarysection including aprimary electronsource anda primary anode, said primary anode containing an aperturefor. the escape of primary electrons therethrough, said secondarysection comprising asecondary electron source for emitting electrons inratio greater than unity when bombarded with primary electrons and asecondary electron collector electrode, said secondary source andcollector electrode being positioned out-of the direct path of escapedelectrons,.and an additional electrode; means for maintaining saidadditional electrode at a potential such that escaped electrons areattracted thereto; and means comprising a coil which, when traversed bycurrent, produces magnetic flux perpendicular to the axis of the device,for deflecting the escaped electrons :away from said additionalelectrode and onto said secondary source.

2. The combination of claim 1 in which the magnetic flux makes arelatively small angle with respect to the plane of the collectorelectrode.

3. The combination of claim 1 in which the magnetic flux makes an angleof approximately four degrees with respect to the plane of the collectorelectrode.

. 4. The combination of claim 1 in which current flow in eitherdirection through the coil is effective to produce magnetic fluxdeflecting the escaped electrons onto the auxiliary anode.

5. In combination, an electronic device comprising a primary electronsection and a secondary electron section, said primary section includinga primary electron source and a primary anode, said primary anodecontaining an aperture for the escape of primary electrons therethrough,said secondary section comprising a secondary electron source foremitting electrodes in ratio greater than unity when bombarded withprimary electrons and a secondary electron collector electrode, saidsecondary source and collector electrode bein positioned out of thedirect path of escaped electrons, and an additional electrode;

means for maintaining said additional electrode at a potential such thatescaped electrons areattracted thereto; means comprising a coil which,when traversed by current, produces magnetic flux perpendicular to theaxis of the device, for deflecting the escaped electrons away from saidsource; and means interconnecting the secondary section and the primarysection such that changes in potential in the secondary section uponsecondary electron emission by said secondary source when the escapedelectrons are deflected thereonto sharply increases the magniture ofprimary electron flow in said primary section.

6. The combination of claim in which current fiow in either directionthrough the coil is effecondary electron source for emitting electronsratio greater than unity when bombarded with primary electrons and asecondary electron collector electrode, said secondary source andcollector electrode being positioned out of the direct path of escapedelectrons, and an additional elec-- additional electrode and onto saidsecondary tron flow limiting means such that changes in potential in thesecondary section upon secondary electron emission by said secondarysource when escaped electrons are deflected thereonto, compensates ,saidlimiting means whereby the magnitude of the primary electron flowincreases sharply.

8. The combination of claim 7, in which the current how in eitherdirection through the coil is effective to producemagn'etic fluxdeflecting the escaped electrons onto the secondary source.

h. A pulse counting circuit comprising a plurality of interconnectedvacuum electronic devices, each of said devices including a primaryelectron source and a primary anode between which an electron stream maybe established and a secondary electron emission electrode; means forestablishing secondary electron emission in one of said devices and forpriming, a second ,of said devices for establishment of secondaryeiectron emission in said second device; and means, including aconnection between the primary anodes of said devices, for establishingsecondary electron emission in said second device and for simultaneouslydisestablishing the secondary electron-emission in said first device.

10. The circuit of claim 9 in which the connection between the primaryanodes includes a reactance.

11. The circuit of claim 9 in which the connection between the primaryanodes includes a negative react'ance.

12. In combination, a plurality of vacuum electronic devices, eachdevice comprising a primary electron section and a secondary electronsection, said primary electron section comprising a primary electronsource and aprimary anode, and said secondary electron sectioncomprising a secondary electron source and a secondary electroncollecting electrode; means for establishing secondary electron emissionin the secondary secticn of one device and for increasing the magnitudeof primary electron flow in the primary section of said one device;means for priming a second of said devices for secondary electronemission, said priming means including a coil connected to the primaryelectron section of said first-mentioned device for producing a magneticfield in said second-mentioned device; and means for increasing thestrength of said magnetic field sufficiently to establish secondaryelectron emission in the secondary section of said sec0ndmentioneddevice, to increase the magnitude of primary electron flow in theprimary section of said second-mentioned device and to disestablishsecondary electron emission in' said first-mentioned device.

13. The combination of claim 12 in which the last-mentioned meansincludes a, second coil for producing a magnetic field aiding that ofthe first-mentioned coil.

14. The combination of claim 12 in'which the last-mentioned'meansincludes an interconnection between the primary section of said firstand second-mentioned devices whereby change in potential on the primaryanode of the primary section of the second-mentioned device on increaseof primary electron flow in the latter, reduces the potential on theprimary anode of the primary section of the first-mentioned device to avalue below that required to sustain secondary electron emission in thefirst-mentioned device.

15,. In combination, a. plurality of yacuum electronic devices, eachdevice comprising a primary electron section and a secondary electronsection; means for establishing secondary electron emission in thesecondary section of one device and for increasing the magnitude ofprimary electron flow in the primary section of said one device; meansfor priming a second of said devices for secondary electron emission,said priming means including a coil connected to the primary section ofsaid first-mentioned device for producing a magnetic field in saidsecondmentioned device; and means for increasing the strength of saidmagnetic field sufiiciently to establish secondary electron emission inthe secondary section of said second-mentioned device to increase themagnitude of primary electron fiow in the primary section of saidsecond-mentioned device and to disestablish secondary electron emissionin said first-mentioned device.

16. The combination of claim 15 in which said last-mentioned meansincludes a second coil for producing a magnetic field aiding that of thefirst-mentioned coil.

17. The combination of claim 15 in which said last-mentioned meansincludes an interconnection between the primary sections of said firstand second-mentioned devices.

18. The combination of claim 15 in which said last-mentioned meansincludes a reactive interconnection between the primary sections of saidfirst and second-mentioned devices.

19. The combination of claim 15 in which said last-mentioned meansincludes a negative reactance interconnection between the primarysections of said first and second-mentioned devices.

20. A pulse counting circuit comprising aplurality of vacuum electronicdevices, each device comprising a primary electron section anda'secondary electron section, said primary section including a primaryelectron source and a primary anode, and said secondary sectioncomprising a secondary electron source and a secondary electroncollecting electrode; pulse responsive means for establishing secondaryelectron emission in the secondary section of one of said devices andfor increasing the magnitude of primary electron flow in the primarysection thereof; means for priming a second of said devices forsecondary electron emission; pulse responsive means for establishingsecondary electron emission in the secondary section of saidsecond-mentioned device and for increasing themagnitude of primaryelectron flow in the primary section of said second-mentioned device;and means interconnecting the primary anodes of the primary sections ofsaid devices for disestablishing secondary electron emission in thefirst-mentioned device upon the increasing in the primary electron flowin said second-mentioned device.

21. The circuit of claim 20 in which said lastmentioned meansdisestablishes secondary electron emission in the first-mentioned deviceby sharply reducing the potential on the primary anode of the primarysection of said first-mentioned device.

22. The circuit of claim 20 in which the interconnecting means comprises-a reactance.

23. The circuit of claim 20 in which the interconnecting means comprisesa negative reactance.

24. The circuit of claim 20 in which the interconnecting means comprisesa condenser.

25. A pulse counting circuit comprising a plurality of vacuum electronicdevices, each device comprising a primary electron section and asecondary electron section; pulse responsive means for establishingsecondary electron emission in the secondary section of one of saiddevices andfor'increasing the magnitude of primary electron flow in theprimary section thereof; means for priming a second of said devices forsecondary electron emission therein, said means comprising a magneticfield producing coil connected to the primary section of saidfirst-mentioned device; pulse responsive means for establishing.

secondary electron emission in the secondary section of saidsecond-mentioned device and for increasing the magnitude of primaryelectron flow in the primary section of said second-mentioned device,said second-mentioned pulse responsive means including a second coil forproducing a magnetic field aiding the field of the first-mentioned coil;and means interconnecting said auxiliary control electrode being in thenormal path of said escaped electrons and said secondary source beingout of the normal path of said escaped electrons; means for initiallybiasing each control electrode so that a low value of primary electronflow exists between said primary source and said primary anode of therespective device; means to maintain each auxiliary control electrode ata potential positive with respect to the primary source such that theescaped electrons are normally attracted to the auxiliary controlelectrode; means interconnecting said secondary source and said firstcontrol electrode of the; respective device; a common source ofpotential for the primary anodes of the devices; a coil connectedbetween each primary anode and said source of potential; a, condenserconnected between the primary anodes of said devices; and a second 0011'ALBERT M. exam-err.

